Carbon nanotubes (CNT) have elongated tubular bodies which are typically only a few atoms in circumference. Carbon nanotubes are hollow and typically have a linear fullerene structure. The length of the carbon nanotubes potentially may be thousands or millions of times greater than their diameter. Both single-walled carbon nanotubes (SWNT) and multi-walled carbon nanotubes (MWNT) are known in the art.
Decoration of the walls of carbon nanotubes with functional groups and/or nanoparticles has been performed to add additional functionality to carbon nanotubes. See, Ebbesen, J. Phys. Chem. Sol. 1996; 57(6-8):951-5 and Rakov, Chemistry of Carbon Nanotubes In: Gogotsi Y, editor, Nanomaterials Handbook, Boca Raton, Fla.: CRC Press; 2006, p. 105-75. In the recent years, decoration of CNT has been used to increase the hydrogen storage capacity (Mu, et al., Carbon 2006; 44(4): 762-7), to make nanotubes magnetic (Gao, et al., J. Phys. Chem. B. 2006; 110(14): 7213-20), and to grow secondary structures inside the nanotubes to increase the available surface for catalysis (Zhao, et al., Carbon 2006; 44(7): 1310-3). Functionalization of the interior walls of carbon nanotubes, in particular those produced using a non-catalytic template-assisted chemical vapor deposition method (CVD), has been achieved using different methods, such as direct fluorination (Hattori, et al., Carbon 1999; 37(7): 1033-8), nitric acid treatment (Kyotani, et al., Carbon 2001; 39: 782-5), and filling with magnetic (Komeva, et al., Nano Lett. 2005; 5(5): 879-84) and fluorescent nanoparticles (Kim, et al., Nano Lett. 2005; 5(5): 873-8). Despite the work that has been done in this area, there is a need for more efficient processes for functionalizing nanoparticles.